Boosted H2O2 activation for water decontamination via biomass carbon dots/WO3-x composites: The role of Z-scheme charge transfer pathway and dual reaction centers

Jialin Lu; Bing Shen; Wenwen Qu; Li Zhao; Shu Yang; Qi Liu; Yihui Liu

doi:10.1016/j.biortech.2025.132837

Boosted H₂O₂ activation for water decontamination via biomass carbon dots/WO_3-x composites: The role of Z-scheme charge transfer pathway and dual reaction centers

Bioresour Technol. 2025 Jun 20:435:132837. doi: 10.1016/j.biortech.2025.132837. Online ahead of print.

Authors

Jialin Lu¹, Bing Shen¹, Wenwen Qu², Li Zhao³, Shu Yang¹, Qi Liu¹, Yihui Liu¹

Affiliations

¹ Faculty of Science, Kunming University of Science and Technology, Kunming 650500, PR China.
² Faculty of Science, Kunming University of Science and Technology, Kunming 650500, PR China; Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, PR China; National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming University of Science and Technology, Kunming 650093, PR China. Electronic address: qwwen1977@126.com.
³ Faculty of Science, Kunming University of Science and Technology, Kunming 650500, PR China. Electronic address: 759418259@qq.com.

PMID: 40545051
DOI: 10.1016/j.biortech.2025.132837

Abstract

Photo-Fenton-like catalytic reactions exhibit remarkable effectiveness in environmental remediation owing to the synergistic interaction between photocatalysis and peroxide activation. Herein, biomass carbon quantum dots (BCDs) derived from pomelo peels were used to modulate BCDs/WO_3-x (BW) composites with dual reaction centers via a microwave-induced solvothermal approach, forming an iron-free photo-Fenton-like system (PFLS). Driven by the built-in electric field across the BW heterointerface, a Z-scheme charge transfer route was elucidated, which endows rapid photoexcited electron transfer from the WO_3-x to the BCDs. Notably, the dual reaction centers on BCDs and electron-rich oxygen vacancies of WO_3-x acted as both electron transmission "channel" and electron "reservoir", thereby accelerating the redox cycle of W⁶⁺/W⁵⁺ to phenomenally enhanced production of ¹O₂ and ·O₂^- species involving interfacial reactions. Simulated adsorption and cleavage behaviors of H₂O₂ on BW revealed a lower Gibbs free energy difference (ΔG) for ¹O₂ evolution (1.90 eV) compared to ‧OH (4.10 eV) evolution. The optimal BW-10 PFLS is efficient in various pollutants removal, with the maximum degradation rate constant (k) for RhB being 25.9 and 6.4 times higher than that of conventional Fenton-like and photocatalytic systems, respectively. It also exhibited outstanding synergistic degradation performance with 83.2 % TC-HCl and 98.6 % RhB removal in their mixed solution. Meanwhile, the BW-10 PFLS had excellent recyclability and anti-interference capability in complex real water matrices. Additionally, the bean sprout growth experiments demonstrated the negligible toxicity of the degradation products in the BW-10 PFLS. This work provides a fresh insight into the design of WO_3-x-based photo-Fenton-like photocatalysts for environmental remediation.

Keywords: BCDs/WO(3-x) composites; DFT calculations; Dual reaction centers; H(2)O(2) activation; photo-Fenton-like degradation.